Blood Brain Barrier

Question 1

How does the meninges protect the brain?

Answer 1

Protective menbranes

Question 2

How does the skull and vertebral column protect the brain?

Answer 2

Structure

Question 3

How does the cerebrospinal fluid (CFS) protect the brain?

Answer 3

Cushioning and protection

Question 4

How does the BBB protect the brain?

Answer 4

-Highly selective - controls the in/out of the brain
-Limits access from the blood

Question 5

What do the meninges surround?

Answer 5

The brain

Question 6

One of the three membranes around the meninges is the Dura mater, where is this?

Answer 6

Strong outer layer

Question 7

One of the three membranes around the meninges is the Arachnoid mater, what is this like?

Answer 7

It is highly vascularised

Question 8

One of the three membranes around the meninges is the Pia mater, what is this like?

Answer 8

Gentle, thin membrane, adheres to the brain tissue.

Question 9

What are the spinal meninges called?

Answer 9

-Pia mater
-Arachnoid mater
-Dura mater

Question 10

Keeping the neurons in the brain in a highly controlled environment is what for function?

Answer 10

Critical

Question 11

What are the 2 main extracellular compartments of the brain?

Answer 11

-CSF: in the ventricles and central canal of the spinal cord
-Interstitial: the space containing the interstitial fluid surrounding the cells of the CNS

Question 12

How many ventricles are there in the brain?

Answer 12

4

Question 13

What are the ventricles lined with?

Answer 13

Ciliated ependymal cells

Question 14

How much CSF do you have roughly in ml’s?

Answer 14

125-150ml

Question 15

How does the composition of CSF differ from that of blood?

Answer 15

The composition of CSF is highly regulated and differs from blood; it contains less potassium, more sodium and no protein

Question 16

What is the role of CSF in relation to brain tissue?

Answer 16

CSF has the same density as brain tissue and acts as a shock absorber

Question 17

What is the CSF fluid secreted by?

Answer 17

Epithelial cells of the choroid plexuses in the ventricles

Question 18

What does the CSF exit via?

Answer 18

Arachinoid villi

Question 19

The BBB is highly regulated via what?

Answer 19

K, can change in he blood but will not change in the interstitial fluid, and this is because the BBB is highly regulated by controlling what goes in and out

Question 20

If a substance move from the blood into the brain interstitial fluid, what must it do?

Answer 20

Pass through the endothelial cell

Question 21

This describes what part of the BBB?

-Allows substances to move in/out
-Aqueous pathways ‘pores’ between endothelial cells
-Vesicular transport - pinocytosis, endocytosis
-May have fenestrations through the endothelial.

Answer 21

General capillary

Question 22

This describes what part of the BBB?
-Cerebral microvascular endothelial cells have tight junctions (no pores)
-Pericytes
-Astrocyte food processes also surround the capillary
-Maintenance of the tight junctions

Answer 22

Blood capillary

Question 23

Circumventricular organs are outside the BBB, what are examples of these?

Answer 23

Posterior pituitary
and
The area postrema (Chemoreceptor trigger zone)

Question 24

What is the function of the posterior pituitary?

Answer 24

Secretes protein hormones, we need to enter into periphery, blood vessels need to be leaky enough to do that = no BBB

Question 25

What is the function of the area postrema?

Answer 25

Causes vomiting, senses toxic indulgence!

Question 26

What isolates the rest of the brain from the BBB?

Answer 26

Tanycytes, the tanycytic membrane